The amount of online content downloaded over computer networks is rapidly increasing with time due to multiple factors: popularity of online video streaming and user-generated content, proliferation of social networks and media-rich messaging, cloud-based storage etc.
Requested content often must be delivered over long distances. Only the most popular videos can be cached near the user. Content that uses secure protocols like HTTPS can't be cached without disclosing at least some encryption keys to third parties. Remote viewing of events streamed in real time such as sports and news can't use caching. Local content is often not cached outside of the countries of origin.
Increase of the data travel distance often increases the rate of packet losses. If connection uses guaranteed-delivery protocol such as Transport Control Protocol (TCP), these losses are usually interpreted as last-mile congestion, resulting in significant decrease in the throughput even if each segment of the connection pipe is far from the saturation point.
Spreading the data transfer across multiple simultaneous guaranteed-delivery transport connections between the sender and the receiver usually increases the total throughput: adding each new connection increases the aggregated size of both receiver and congestion windows, allowing more data to be delivered during each round-trip interval. The speed of transferring large data files over the long distances increases with the number of simultaneous connections, until at least one segment of the connection pipe becomes congested or resources of the server and client computers (memory, CPU load, I/O capacity) become overstrained.
Therefore, there is a need to increase the speed of data transfer over the multiple simultaneous connections for real-life scenarios, including bursts of limited-size data files.